A communications device can be understood as a device provided with appropriate communication and control capabilities for enabling use thereof for communication with other parties. The communication may comprise, for example, communication of voice, electronic mail (email), text messages, data, multimedia and so on. A communication device typically enables a user of the device to receive and transmit communications via a communications system and can thus be used for accessing various applications.
A communications system is a facility which facilitates the communication between two or more entities such as the communications devices, network entities and other nodes. An appropriate access system allows the communications device to access the communications system. An access to the communications system may be provided by means of a wireless communication interface.
Communications systems providing wireless access typically enable at least some mobility for the users thereof. Examples of these include cellular wireless communications systems where the access is provided by means of access entities called cells. Other examples of wireless access technologies include different wireless local area networks (WLANs) and satellite based communications systems.
A wireless communications system typically operates in accordance with a wireless standard and/or with a set of specifications which set out various aspects of the wireless interface. For example, the standard or specification may define if the user, or more precisely user equipment, is provided with a circuit switched bearer or a packet switched bearer, or both. Communication protocols and/or parameters which should be used for a wireless connection are also typically defined. For example, the frequency band or bands to be used for the communications are typically defined.
A portable communications device may be provided with so called multi-radio capabilities. That is, a portable device may be used for communication via a plurality of different wireless interfaces. An example of such device is a multi-mode cellular phone, for example a cellular phone that may communicate in at least two of the GSM (Global System for Mobile communications) frequency bands 850, 900, 1800 and 1900 MHz or a cellular phone that may communicate based on at least two different standards, for example a cellular phone which may operate on at least two of the GSM access network, the CDMA (Code Division Multiple Access) access network, and a WCDMA (Wideband CDMA) based access network as used in the UMTS (Universal Mobile Telecommunications System).
A mobile or portable device may also be configured for communication via at least one cellular system and at least one non-cellular system. Non-limiting examples of the latter include short range radio links such as Bluetooth™, other access networks such as wireless local area networks (WLAN) and ultra wide band (UWB).
Furthermore a mobile or portable device may also be configured for receiving information broadcast systems, non limited examples including those based on the Digital Video Broadcasting via Handheld Terminals (DVB-H), and global positioning system (GPS).
Such communications devices can be implemented with software defined radio (SDR) methods. In an SDR system, a radio receiver/transmitter can be configured to potentially tune to any frequency band and receive/transmit any known modulation scheme across a large frequency spectrum and process signals through the use of software.
A multi radio communications device equipped with SDR capabilities may have to be able to handle simultaneously more than one active radio connection. This increases the required complexity of any RF system on chip (RF SOC) in the communications device since the RF SOC has to enable cooperation in the control plane between the different communication systems in order to enable seamless multi radio operation. The complexity of such RF system on chip designs is also increased as any cost effective design involving multi radio communication capability will require some sharing of common resources of which the shared resources need to be controlled and allocated when necessary.
The increased complexity of such designs has meant that it is unfeasible for a single design team to produce a RF system on chip (SoC) design and it is currently best practice for some parts of the RF SoC to be designed inside a company by one or more teams, whilst the design of other parts of the RF SoCs is sub-contracted out to external designers, and other parts of the RF SoC formed from recycled previous designs.
It is thus desirable for such RF Systems on Chip designs to have a modular architecture allowing easy integration of various components of the RF. However the arrangement and operation of such architectures is difficult to implement, particularly in software defined radio systems when it is required to be able to make changes to the operation of the RF modules.
There have been developments with respect to the creation of low level hardware driver interfaces, however these typically are limited to dealing with only one level of extraction. For example there has been an initiative to parameterize the RF hardware and circuitry by such forum and standards groups as the Software Defined Radio forum and the Object Management Group (OMG) with their Software Communications Architecture (SCA).
These existing approaches however lack flexibility, especially when possible hardware architecture changes are required to be implemented.